What durch word are you seeing in documentation to denote sponser ?? what sort of document is it ?? I have marriage for the 1700 and 1700's and all I ever see on those is
Getuige bij het huwelijk - witness to the marriage
One of my ancestors Gertrudis Deckers (Dekkers) married Matthias Veugelaers (Veugelers) in 1738. She and her husband had 2 sponsors: both had the same last name Gertrudis had.
Typically when people got married, did they have siblings as their sponsors?